outlookcaldavsynchronizer/GenSync/IdWithHints.cs

// This file is Part of CalDavSynchronizer (http://outlookcaldavsynchronizer.sourceforge.net/)
// Copyright (c) 2015 Gerhard Zehetbauer
// Copyright (c) 2015 Alexander Nimmervoll
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
// 
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using System;

namespace GenSync
{
    public static class IdWithHints
    {
        public static IIdWithHints<TEntityId, TVersion> Create<TEntityId, TVersion>(TEntityId id, TVersion versionHint, bool? wasDeletedHint) where TVersion : class
        {
            return new IdWithHintsClass<TEntityId, TVersion>(id, versionHint, wasDeletedHint);
        }

        public static IIdWithHints<TEntityId, TVersion> Create<TEntityId, TVersion>(TEntityId id, TVersion? versionHint, bool? wasDeletedHint) where TVersion : struct
        {
            return new IdWithHintsStruct<TEntityId, TVersion>(id, versionHint, wasDeletedHint);
        }

        private class IdWithHintsClass<TEntityId, TVersion> : IIdWithHints<TEntityId, TVersion>
            where TVersion : class
        {
            public TEntityId Id { get; private set; }
            public TVersion VersionHint { get; private set; }
            public bool IsVersionHintSpecified => VersionHint != null;
            public bool? WasDeletedHint { get; private set; }

            public IdWithHintsClass(TEntityId id, TVersion versionHint, bool? wasDeletedHint)
            {
                Id = id;
                VersionHint = versionHint;
                WasDeletedHint = wasDeletedHint;
            }
        }

        private class IdWithHintsStruct<TEntityId, TVersion> : IIdWithHints<TEntityId, TVersion>
            where TVersion : struct
        {
            private readonly TVersion? _version;

            public TEntityId Id { get; private set; }

            // ReSharper disable once PossibleInvalidOperationException
            public TVersion VersionHint => _version.Value;
            public bool IsVersionHintSpecified => _version.HasValue;
            public bool? WasDeletedHint { get; private set; }

            public IdWithHintsStruct(TEntityId id, TVersion? version, bool? wasDeletedHint)
            {
                Id = id;
                _version = version;
                WasDeletedHint = wasDeletedHint;
            }
        }
    }
}